Method of manufacturing a semiconductor device

Abstract

After a catalyst element is introduced into an amorphous silicon film, the amorphous silicon film is converted into a crystalline silicon film by a heat treatment and laser irradiation. After a resist mask is formed on the crystalline silicon film, boron and phosphorus are selectively introduced into the crystalline silicon film to form a gettering region therein. Then, a heat treatment is performed at 500°-650° C., whereby the catalyst element in a gettering subject region is gettered to the gettering region. As a result, a crystalline semiconductor film is obtained in which the catalyst element concentration is reduced. The crystalline semiconductor film is patterned into a semiconductor layer of a semiconductor device.

What is claimed is:  
     
       1. A method of manufacturing a semiconductor device comprising the steps of: 
       forming a semiconductor film comprising amorphous silicon over a substrate;  
       introducing a crystallization promoting material into the semiconductor film;  
       crystallizing the semiconductor film;  
       introducing a group-13 impurity element and a group-15 impurity element into a portion of the crystallized semiconductor film to form a gettering region;  
       heating the crystallized semiconductor film so that the crystallization promoting material is moved to the gettering region; and  
       patterning the crystallized semiconductor film so that the gettering region is removed,  
       wherein the gettering region contains the group-13 impurity element at a concentration equal to or higher than that of the group-15 impurity element.  
     
     
       2. A method according to  claim 1  wherein the crystallization promoting material comprises at least one element selected from the group consisting of Ni, Co, Fe, Pd, Pt, Cu, and Au. 
     
     
       3. A method according to  claim 1  wherein the group-13 impurity element comprises at least one element selected from the group consisting of B, Al, Ga, In, and Tl. 
     
     
       4. A method according to  claim 1  wherein the group-15 impurity element comprises at least one element selected from the group consisting of N, P, As, Sb, and Bi. 
     
     
       5. A method according to  claim 1  wherein the gettering region contains the group-13 impurity element at a concentration by 1 to 3 times higher than that of the group-15 impurity element. 
     
     
       6. A method of manufacturing a semiconductor device comprising the steps of: 
       forming a semiconductor film comprising amorphous silicon over a substrate;  
       introducing a crystallization promoting material into the semiconductor film;  
       crystallizing the semiconductor film;  
       introducing a group-13 impurity element and a group-15 impurity element into a portion of the crystallized semiconductor film to form a gettering region;  
       heating the crystallized semiconductor film so that the crystallization promoting material is moved to the gettering region; and  
       patterning the crystallized semiconductor film so that at least a portion of the gettering region is removed,  
       wherein the gettering region contains the group-13 impurity element at a concentration equal to or higher than that of the group-15 impurity element.  
     
     
       7. A method according to  claim 6  wherein the crystallization promoting material comprises at least one element selected from the group consisting of Ni, Co, Fe, Pd, Pt, Cu, and Au. 
     
     
       8. A method according to  claim 6  wherein the group-13 impurity element comprises at least one element selected from the group consisting of B, Al, Ga, In, and Tl. 
     
     
       9. A method according to  claim 6  wherein the group-15 impurity element comprises at least one element selected from the group consisting of N, P, As, Sb, and Bi. 
     
     
       10. A method according to  claim 6  wherein the gettering region contains the group-13 impurity element at a concentration by 1 to 3 times higher than that of the group-15 impurity element. 
     
     
       11. A method of manufacturing a semiconductor device comprising the steps of: 
       forming a gate electrode over a substrate;  
       forming a gate insulating film over the gate electrode,  
       forming a semiconductor film comprising amorphous silicon over the gate insulating film;  
       introducing a crystallization promoting material into the semiconductor film;  
       crystallizing the semiconductor film;  
       introducing a group-13 impurity element and a group-15 impurity element into a portion of the crystallized semiconductor film to form a gettering region;  
       heating the crystallized semiconductor film so that the crystallization promoting material is moved to the gettering region; and  
       patterning the crystallized semiconductor film so that the gettering region is removed,  
       wherein the gettering region contains the group-13 impurity element at a concentration equal to or higher than that of the group-15 impurity element.  
     
     
       12. A method according to  claim 11  wherein the crystallization promoting material comprises at least one element selected from the group consisting of Ni, Co, Fe, Pd, Pt, Cu, and Au. 
     
     
       13. A method according to  claim 11  wherein the group-13 impurity element comprises at least one element selected from the group consisting of B, Al, Ga, In, and Tl. 
     
     
       14. A method according to  claim 11  wherein the group-15 impurity element comprises at least one element selected from the group consisting of N, P, As, Sb, and Bi. 
     
     
       15. A method according to  claim 11  wherein the gettering region contains the group-13 impurity element at a concentration by 1 to 3 times higher than that of the group-15 impurity element. 
     
     
       16. A method of manufacturing a semiconductor device comprising the steps of: 
       forming a gate electrode over a substrate;  
       forming a gate insulating film over the gate electrode,  
       forming a semiconductor film comprising amorphous silicon over the gate insulating film;  
       introducing a crystallization promoting material into the semiconductor film;  
       crystallizing the semiconductor film;  
       introducing a group-13 impurity element and a group-15 impurity element into a portion of the crystallized semiconductor film to form a gettering region;  
       heating the crystallized semiconductor film so that the crystallization promoting material is moved to the gettering region; and  
       patterning the crystallized semiconductor film so that at least a portion of the gettering region is removed,  
       wherein the gettering region contains the group-13 impurity element at a concentration equal to or higher than that of the group-15 impurity element.  
     
     
       17. A method according to  claim 16  wherein the crystallization promoting material comprises at least one element selected from the group consisting of Ni, Co, Fe, Pd, Pt, Cu, and Au. 
     
     
       18. A method according to  claim 16  wherein the group-13 impurity element comprises at least one element selected from the group consisting of B, Al, Ga, In, and Tl. 
     
     
       19. A method according to  claim 16  wherein the group-15 impurity element comprises at least one element selected from the group consisting of N, P, As, Sb, and Bi. 
     
     
       20. A method according to  claim 16  wherein the gettering region contains the group-13 impurity element at a concentration by 1 to 3 times higher than that of the group-15 impurity element. 
     
     
       21. A method of manufacturing a semiconductor device comprising the steps of: 
       forming a semiconductor film comprising amorphous silicon over a substrate;  
       introducing a crystallization promoting material into the semiconductor film;  
       crystallizing the semiconductor film;  
       introducing a group-13 impurity element and a group-15 impurity element into a portion of the crystallized semiconductor film to form a gettering region;  
       heating the crystallized semiconductor film at a temperature of 400-1050° C. so that the crystallization promoting material is moved to the gettering region; and  
       patterning the crystallized semiconductor film so that the gettering region is removed,  
       wherein the gettering region contains the group-13 impurity element at a concentration equal to or higher than that of the group-15 impurity element.  
     
     
       22. A method according to  claim 21  wherein the crystallization promoting material comprises at least one element selected from the group consisting of Ni, Co, Fe, Pd, Pt, Cu, and Au. 
     
     
       23. A method according to  claim 21  wherein the group-13 impurity element comprises at least one element selected from the group consisting of B, Al, Ga, In, and Tl. 
     
     
       24. A method according to  claim 21  wherein the group-15 impurity element comprises at least one element selected from the group consisting of N, P, As, Sb, and Bi. 
     
     
       25. A method according to  claim 21  wherein the gettering region contains the group-13 impurity element at a concentration by 1 to 3 times higher than that of the group-15 impurity element. 
     
     
       26. A method of manufacturing a semiconductor device comprising the steps of: 
       forming a semiconductor film comprising amorphous silicon over a substrate;  
       introducing a crystallization promoting material into the semiconductor film;  
       crystallizing the semiconductor film;  
       introducing a group-13 impurity element and a group-15 impurity element into a portion of the crystallized semiconductor film to form a gettering region;  
       heating the crystallized semiconductor film at a temperature of 400-1050° C. so that the crystallization promoting material is moved to the gettering region; and  
       patterning the crystallized semiconductor film so that at least a portion of the gettering region is removed,  
       wherein the gettering region contains the group-13 impurity element at a concentration equal to or higher than that of the group-15 impurity element.  
     
     
       27. A method according to  claim 26  wherein the crystallization promoting material comprises at least one element selected from the group consisting of Ni, Co, Fe, Pd, Pt, Cu, and Au. 
     
     
       28. A method according to  claim 26  wherein the group-13 impurity element comprises at least one element selected from the group consisting of B, Al, Ga, In, and Tl. 
     
     
       29. A method according to  claim 26  wherein the group-15 impurity element comprises at least one element selected from the group consisting of N, P, As, Sb, and Bi. 
     
     
       30. A method according to  claim 26  wherein the gettering region contains the group-13 impurity element at a concentration by 1 to 3 times higher than that of the group-15 impurity element.